Given all of that, one would have to believe it is sending oil to the cylinders. Can you notice the hoses move some (flex) when you try to tilt the bucket? You could disconnect a hose and see if oil flies when you move the valve. Just make sure you think through all the safety issues there. Finally, if there's oil getting to the cylinders then the seals on one of the pistons inside of the cylinders must be bad leaving oil by. New Holland does sell a rebuild kit. If you have a big pipe wrench and a serious impact gun I can tell you how we went about rebuilding ours. For us, the seal where the rod comes out of the cylinder would usually fail. Very seldom did the piston seals cause us issues, but that could be a difference in how the machines are used.